Last modified 10/15/2002                                                                        [Back to Top]  Direct Access Quick View Local Search Distributed Search DIAL is a WWW based data distribution system. It allows data providers to easily serve their Earth science data directly to their users. DIAL provides traditional catalog services like metadata search, while also providing extended interactive data services like browsing, subsetting, subsampling, reformatting and direct downloading. The power of DIAL has recently been enhanced by the addition of the EOSDIS "Version 0" protocol, which enables a project to set up a distributed system of DIAL servers. DIAL supports Hierarchical Data Format (HDF) and HDF for EOS (HDF-EOS) formatted datasets. DIAL also provides interoperability with GIS systems through traslators. DIAL software has been tested using Netscape 4.0.5, 4.0.6 and MS Internet Explorer 4.0 (It should work with later versions of the browsers.) Current version of DIAL is 3.0 (Release Notes). Data providers can choose any of the following different ways to distibute scientific data and provide data services: Direct Access This method is suitable for data providers to distribute a small number of static data files to data users. No catalog search is available in this approach.  Click this link to view an example HDF-EOS data file using the direct access method. Quick View (Transient Area) This method is suitable for data providers who are required to provide a quick view of data without a metadata catalog.  In this approach the catalog search will not be available.  This approach is best suited for Quality Assurance environment.  This site has several quick look areas: Example HDF and HDF-EOS data files Hantavirus Risk Maps START/SEADIS data files IGRID Demo data files TERRA data files Local Search In this method, DIAL can be used as a stand alone data server.  By using DIAL in this way, both DIAL search and data access capabilities are provided to the data users. If the data provider has a large number of data files to be distributed, this method is recommended.  Click this link to search our DIAL test site (Java enabled browser required).  Users with non-Java enabled browsers can use our simple HTML search interface. Distributed Search This method is appropriate for any project with multiple DIAL sites interested in providing a single user interface to search all the sites.  Individual DIAL sites can be integrated with the EOS Data Gateway system (formerly EOSDIS Version 0 IMS) forming a distributed data search and access system. Click this link to search our DIAL test site through our test gateway (a separate EOS Data Gateway installed for our testing purposes). Click this link to search ESIP Federation SWIL Testbed server. NOTE: For most standalone data distribution systems, Local Search provides the best balance of user features and provider responsibilities.   DIAL Metadata Catalog DIAL can implement its inventory catalog as a flat file or as a JDBC-compatible database file.   Click this link to view the catalog structure of our test site. Acknowledgement The HDF file browser was developed by the HDF Group at NCSA. We have extended the browser with additional viewing and subsetting functions in close cooperation with the HDF Group. The original source code of the NCSA Science Data Browser is available from NCSA's SDB home page. Visit this link to find out more about the DIAL development team. Contact: Dial Help NASA Official: Ken McDonald (ken.mcdonald@gsfc.nasa.gov) NASA SECURITY POLICY [DIAL Home][DIAL Demo][Get This Software][Documentation][FAQ][Selected DIAL Sites][Related Links]